Pali gate will not place between correct corner posts

[Dondy]

I am building an outer pali two tiles distant from an existing pali. There are four gate posts, lined up. The two posts to the south are sealed and have a three tile wide visitor gate in them. I need to place a second gate between the two new corner posts to the north. However whenever I click to build the gate between them it attempts to place a two tile wide gate between one of the old corner posts and the new. I definitely do not want a gate between the north and south posts, but I am not being given the correct option.

It also locks my character in place. I have to log the character out to get away from the interaction displaying the unwanted gate. I can hearth but I am still locked in place unable to walk away from my hearth fire.

Suggestions?

[SnuggleSnail]

Extend the palisade one tile from the cornerpost you're starting the gate at in every direction you don't want the gate to be built in. Build one block into each of the extensions, place the gate, then break the wall signs.